elegans catenin

The F-actin, spectrin, and microtubule cytoskeletons are important mediators of embryonic epidermal morphogenesis in Caenorhabditis elegans . While SMA-1/βH -spectrin is known to organize actin bundles that connect to cadherin-based adhesions, the role of microtubules in the developing epidermis is not well understood. To determine if the spectrin cytoskeleton also plays a role in organizing epidermal microtubules, we conducted feeding RNA interference of four microtubule-associated protein genes in sma-1/ βH -spectrin null animals...

Wnt signalling is one of a few conserved pathways that control diverse aspects of development and morphogenesis in all metazoan species. Endocytosis is a key mechanism that regulates the secretion and graded extracellular distribution of Wnt glycoproteins from the source cells, as well as Wnt signal transduction in the receiving cells. However, controversies exist regarding the requirement of clathrin-dependent endocytosis in Wnt signalling. Various lines of evidence from recent studies suggest that Wnt-β-catenin signalling is also involved in the regulation of cellular stress responses in adulthood, a role that is beyond its canonical functions in animal development...

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No abstract text is available yet for this article.

Wnt/β-catenin signalling has been implicated in the terminal asymmetric divisions of neuronal progenitors in vertebrates and invertebrates. However, the role of Wnt ligands in this process remains poorly characterized. Here, we used the terminal divisions of the embryonic neuronal progenitors in C. elegans to characterize the role of Wnt ligands during this process, focusing on a lineage that produces the cholinergic interneuron AIY. We observed that, during interphase, the neuronal progenitor is elongated along the anteroposterior axis, then divides along its major axis, generating an anterior and a posterior daughter with different fates...

During development, cell fate decisions are often highly stochastic, but with the frequency of the different possible fates tightly controlled. To understand how signaling networks control the cell fate frequency of such random decisions, we studied the stochastic decision of the Caenorhabditis elegans P3.p cell to either fuse to the hypodermis or assume vulva precursor cell fate. Using time-lapse microscopy to measure the single-cell dynamics of two key inhibitors of cell fusion, the Hox gene LIN-39 and Wnt signaling through the β-catenin BAR-1, we uncovered significant variability in the dynamics of LIN-39 and BAR-1 levels...

Exposure to engineered nanomaterials (ENMs), such as graphene oxide (GO), can potentially induce the response of various molecular signaling pathways, which can mediate the protective function or the toxicity induction. Wnt signaling pathway is conserved evolutionarily in organisms. Using Caenorhabditis elegans as an in vivo assay model, we investigated the effect of GO exposure on intestinal Wnt signaling. In the intestine, GO exposure dysregulated Frizzled receptor MOM-5, Disheveled protein DSH-2, GSK-3 (a component of APC complex), and two β-catenin proteins (BAR-1 and HMP-2), which mediated the induction of GO toxicity...

In nematode Caenorhabditis elegans, an intestinal signaling cascade in canonical Wnt/β-catenin signaling pathway, including β-catenin transcriptional factor BAR-1, has been identified to be involved in the control of response to simulated microgravity. However, the downstream target(s) of BAR-1 in regulating the response to simulated microgravity are still unclear. In this study, we found that BAR-1 and its direct target of Wnt effector POP-1 functioned upstream of a Meis TALE-class transcription factor UNC-62 to regulate the response to simulated microgravity...

A correct balance between proliferative and asymmetric cell divisions underlies normal development, stem cell maintenance and tissue homeostasis. What determines whether cells undergo symmetric or asymmetric cell division is poorly understood. To gain insight into the mechanisms involved, we studied the stem cell-like seam cells in the Caenorhabditis elegans epidermis. Seam cells go through a reproducible pattern of asymmetric divisions, instructed by divergent canonical Wnt/β-catenin signaling, and symmetric divisions that increase the seam cell number...

Considering the short life-cycle property, Caenorhabditis elegans is a suitable animal model to evaluate the long-term effects of microgravity stress on organisms. Canonical Wnt/β-catenin signaling is evolutionarily conserved in various organisms. We here investigated the response of canonical Wnt/β-catenin signaling pathway to microgravity stress in nematodes. We observed the noticeable response of canonical Wnt/β-catenin signaling to microgravity stress. In contrast, we did not detect the obvious response of non-canonical Wnt/β-catenin signaling to microgravity stress...

BACKGROUND/AIM: Cetrimonium bromide (CTAB), a quaternary ammonium surfactant, is an antiseptic agent against bacteria and fungi. However, the mechanisms by which its pharmacological actions affect epithelial-mesenchymal transition (EMT) in hepatocellular carcinoma (HCC) cells, such as adenocarcinoma in SK-HEP-1 cells, have not been investigated. We, thereby, investigated whether CTAB inhibits cellular mobility and invasiveness of human hepatic adenocarcinoma in SK-HEP-1 cells. MATERIALS AND METHODS: SK-HEP-1 cells were treated with CTAB, and subsequent migration and invasion were measured by wound healing and transwell assays...

Maintaining tissue integrity during epidermal morphogenesis depends on α-catenin, which connects the cadherin complex to F-actin. We show that the adhesion modulation domain (AMD) of Caenorhabditis elegans HMP-1/α-catenin regulates its F-actin-binding activity and organization of junctional-proximal actin in vivo. Deleting the AMD increases F-actin binding in vitro and leads to excess actin recruitment to adherens junctions in vivo. Reducing actin binding through a compensatory mutation in the C-terminus leads to improved function...

Cadmium is a common environmental pollutant that causes bone damage. However, the effects of cadmium on the osteogenic differentiation of bone marrow mesenchymal stem cells (BMMSCs) and its mechanism of action in this process are unclear. Here, we determined the effects of cadmium chloride (CdCl₂) on the osteogenic differentiation of BMMSCs and the potential mechanism involved in this process. As determined in the present investigation, CdCl₂, in a concentration-dependent manner, affected the viability of BMMSCs and their cytoskeletons...

Niche cell enwrapment of stem cells and their differentiating progeny is common and provides a specialized signaling and protective environment. Elucidating the mechanisms underlying enwrapment behavior has important basic and clinical significance in not only understanding how niches are formed and maintained but also how they can be engineered and how they are misregulated in human pathologies, such as cancer. Previous work in C. elegans found that, when germ cells, which are enwrapped by somatic gonadal niche cells, are freed into the body cavity, they embed into other tissues...

Van Gogh-like (Vangl) and Prickle (Pk) are core components of the non-canonical Wnt planar cell polarity pathway that controls epithelial polarity and cell migration. Studies in vertebrate model systems have suggested that Vangl and Pk may also inhibit signaling through the canonical Wnt/β-catenin pathway, but the functional significance of this potential cross-talk is unclear. In the nematode C. elegans, the Q neuroblasts and their descendants migrate in opposite directions along the anteroposterior body axis...

Lithium has long been used for the treatment of psychiatric disorders, due to its robust beneficial effect as a mood stabilizing drug. Lithium's effectiveness for improving neurological function is therefore well-described, stimulating the investigation of its potential use in several neurodegenerative conditions including Alzheimer's (AD), Parkinson's (PD) and Huntington's (HD) diseases. A narrow therapeutic window for these effects, however, has led to concerted efforts to understand the molecular mechanisms of lithium action in the brain, in order to develop more selective treatments that harness its neuroprotective potential whilst limiting contraindications...

Novel studies have shown that the Transmembrane protein 9 (TMEM9) gene is localized at 1q41 and encodes a protein consisting of 183 amino acids with an N-terminus containing many important domains. As a novel human transmembrane protein, TMEM9 is highly conserved in species from Caenorhabditis elegans to humans and is widely expressed in many tissues and cells. Moreover, TMEM9 may play an important role in intracellular transport and the growth of hepatoma cells. However, evidence for the function of TMEM9 in inflammation is still limited...

Synapses are specialized neuronal connections essential for neuronal function. Defects in synaptic assembly or maintenance usually lead to various neurological disorders. Synaptic assembly is regulated by secreted molecules such as Wnts. Wnts are a large family of conserved glycosylated signaling molecules involved in many aspects of neural development and maintenance. However, the molecular mechanisms by which Wnts regulate synaptic assembly remain elusive due to the large number of ligands/receptors, the diversity of signaling cascades and the complexity of the nervous system...

Adherens junctions (AJs) are key structures regulating tissue integrity and maintaining adhesion between cells. During morphogenesis, junctional proteins cooperate closely with the actomyosin network to drive cell movement and shape changes. How the junctions integrate the mechanical forces in space and in time during an in vivo morphogenetic event is still largely unknown, due to a lack of quantitative data. To address this issue, we inserted a functional Fluorescence Resonance Energy Transfer (FRET)-based force biosensor within HMP-1/α-catenin of Caenorhabditis elegans...

Transcription factors of the Zic family play important roles during animal development, and their misregulation has been implicated in several human diseases. Zic proteins are present in nematodes, and their function has been mostly studied in the model organism C. elegans. C. elegans possesses only one Zic family member, REF-2. Functional studies have shown that this factor plays a key role during the development of the nervous system, epidermis, and excretory system. In addition, they have revealed that the C...